Show file icon on open file MRU drop-down menu items, issue #740.

Co-authored-by: @Sergy2001

src/Helpers.c

@@ -2544,6 +2544,61 @@ void MRU_AddToCombobox(LPCMRULIST pmru, HWND hwnd) {
 	}
 }
 
+void BitmapCache_Empty(BitmapCache *cache) {
+	for (UINT i = 0; i < cache->count; i++) {
+		DeleteObject(cache->items[i]);
+	}
+	memset(cache, 0, sizeof(BitmapCache));
+}
+
+HBITMAP BitmapCache_Get(BitmapCache *cache, LPCWSTR path) {
+	if (cache->invalid) {
+		BitmapCache_Empty(cache);
+	}
+
+	SHFILEINFO shfi;
+	HIMAGELIST imageList = (HIMAGELIST)SHGetFileInfo(path, FILE_ATTRIBUTE_NORMAL, &shfi, sizeof(SHFILEINFO), SHGFI_USEFILEATTRIBUTES | SHGFI_SYSICONINDEX | SHGFI_SMALLICON);
+	const int iIcon = shfi.iIcon;
+	UINT index = 0;
+	for (; index < cache->count; index++) {
+		if (cache->iconIndex[index] == iIcon) {
+			break;
+		}
+	}
+	if (index == cache->count) {
+		NP2_static_assert(sizeof(cache->used)*8 >= MRU_MAXITEMS);
+		if (index < MRU_MAXITEMS) {
+			cache->count += 1;
+		} else {
+			// find first zero bit in used, omitted zero check as used can't be UINT32_MAX
+			// index = __builtin_stdc_first_trailing_one(cache->used);
+			index = np2_ctz(~cache->used);
+			DeleteObject(cache->items[index]);
+			cache->items[index] = NULL;
+		}
+		cache->iconIndex[index] = iIcon;
+	}
+
+	cache->used |= 1U << index;
+	HBITMAP hbmp = cache->items[index];
+	if (hbmp == NULL) {
+		HDC hDC = GetDC(NULL);
+		HDC bitmapDC = CreateCompatibleDC(hDC);
+		RECT rect = { 0, 0, 0, 0 };
+		ImageList_GetIconSize(imageList, (int *)(&rect.right), (int *)(&rect.bottom));
+		hbmp = CreateCompatibleBitmap(hDC, rect.right, rect.bottom);
+		HBITMAP oldBitmap = (HBITMAP)SelectObject(bitmapDC, hbmp);
+		FillRect(bitmapDC, &rect, (HBRUSH)(COLOR_MENU + 1));
+		ImageList_Draw(imageList, iIcon, bitmapDC, 0, 0, ILD_TRANSPARENT);
+		SelectBitmap(bitmapDC, oldBitmap);
+		DeleteDC(bitmapDC);
+		ReleaseDC(NULL, hDC);
+		cache->items[index] = hbmp;
+	}
+
+	return hbmp;
+}
+
 /*
 
  Themed Dialogs

src/Helpers.h

@@ -901,6 +901,23 @@ void MRU_Save(LPCMRULIST pmru);
 void MRU_MergeSave(LPMRULIST pmru, bool keep);
 void MRU_AddToCombobox(LPCMRULIST pmru, HWND hwnd);
 
+typedef struct BitmapCache {
+	UINT count;
+	UINT used;
+	bool invalid;
+	int iconIndex[MRU_MAXITEMS];
+	HBITMAP items[MRU_MAXITEMS];
+} BitmapCache;
+
+static inline void BitmapCache_Invalidate(BitmapCache *cache) {
+	cache->invalid = true; // mark all cache as invalid
+}
+static inline void BitmapCache_StartUse(BitmapCache *cache) {
+	cache->used = 0; // mark all cache as unused
+}
+void BitmapCache_Empty(BitmapCache *cache);
+HBITMAP BitmapCache_Get(BitmapCache *cache, LPCWSTR path);
+
 //==== Themed Dialogs =========================================================
 #ifndef DLGTEMPLATEEX
 #pragma pack(push, 1)

src/Notepad2.c

@@ -255,6 +255,7 @@ static LPWSTR lpEncodingArg = NULL;
 MRULIST mruFile;
 MRULIST mruFind;
 MRULIST mruReplace;
+static BitmapCache bitmapCache;
 
 DWORD	dwLastIOError;
 WCHAR	szCurFile[MAX_PATH + 40];
@@ -1154,6 +1155,7 @@ LRESULT CALLBACK MainWndProc(HWND hwnd, UINT umsg, WPARAM wParam, LPARAM lParam)
 			MRU_MergeSave(&mruFile, bSaveRecentFiles);
 			MRU_MergeSave(&mruFind, bSaveFindReplace);
 			MRU_MergeSave(&mruReplace, bSaveFindReplace);
+			BitmapCache_Empty(&bitmapCache);
 
 			// Remove tray icon if necessary
 			ShowNotifyIcon(hwnd, false);
@@ -1202,12 +1204,14 @@ LRESULT CALLBACK MainWndProc(HWND hwnd, UINT umsg, WPARAM wParam, LPARAM lParam)
 		break;
 
 	case WM_SETTINGCHANGE:
+		BitmapCache_Invalidate(&bitmapCache);
 		// TODO: detect system theme and high contrast mode changes
 		SendMessage(hwndEdit, WM_SETTINGCHANGE, wParam, lParam);
 		Style_SetLexer(pLexCurrent, false); // override base elements
 		break;
 
 	case WM_SYSCOLORCHANGE:
+		BitmapCache_Invalidate(&bitmapCache);
 		SendMessage(hwndToolbar, WM_SYSCOLORCHANGE, wParam, lParam);
 		SendMessage(hwndEdit, WM_SYSCOLORCHANGE, wParam, lParam);
 		Style_SetLexer(pLexCurrent, false); // override base elements
@@ -2137,6 +2141,7 @@ void MsgDPIChanged(HWND hwnd, WPARAM wParam, LPARAM lParam) {
 	const Sci_Line iVisTopLine = SciCall_GetFirstVisibleLine();
 	const Sci_Line iDocTopLine = SciCall_DocLineFromVisible(iVisTopLine);
 
+	BitmapCache_Invalidate(&bitmapCache);
 	// recreate toolbar and statusbar
 	RecreateBars(hwnd, g_hInstance);
 	const int cx = rc->right - rc->left;
@@ -5344,9 +5349,16 @@ LRESULT MsgNotify(HWND hwnd, WPARAM wParam, LPARAM lParam) {
 					return TBDDRET_TREATPRESSED;
 				}
 				hmenu = subMenu = CreatePopupMenu();
+				BitmapCache_StartUse(&bitmapCache);
+				MENUITEMINFO mii;
+				mii.cbSize = sizeof(MENUITEMINFO);
+				mii.fMask = MIIM_STRING | MIIM_BITMAP;
 				for (int i = 0; i < count; i++) {
 					LPCWSTR path = mruFile.pszItems[i];
-					AppendMenu(subMenu, MF_STRING, i + IDM_RECENT_HISTORY_START, path);
+					HBITMAP hbmp = BitmapCache_Get(&bitmapCache, path);
+					mii.dwTypeData = (LPWSTR)path;
+					mii.hbmpItem = hbmp;
+					InsertMenuItem(subMenu, i + IDM_RECENT_HISTORY_START, FALSE, &mii);
 				}
 			} else {
 				hmenu = LoadMenu(g_hInstance, MAKEINTRESOURCE(IDR_POPUPMENU));